Apparatus for selective-signal systems



P. R. MoBERTY. APPARATUS FOR SELEBTIVE SIGNAL SYSTEMS.

(No Model.)

No. 563,294. Patented July 7, 1896.

ran L o 6 6243/ Wifirnyi UNITED STATES i PATENT OFFICE.

FRANK R. MCBERTY, OF DOIVNERS GROVE, ILLINOIS, ASSIGNOR TO THE WVESTERNELECTRIC COMPANY, OF CHICAGO, ILLINOIS.

APPARATUS FOR SELECTIVE-SIGNAL SYSTEMS.

SPECIFICATION forming part of Letters Patent No. 563,294, dated July 7,1896. Application filed August 23, 1895. Serial No. 560,217. (No model.)

To all whom it may concern.-

Be it known that I, FRANK R. MOBERTY, a citizen of the United States,residingat Downers Grove, in the county of Du Page and State ofIllinois, have invented a certain new and useful Improvement inApparatus for Selective-Signal Systems, (Case No. 28,) of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawing, forming a part of thisspecification.

My invention relates to apparatus for oper ating selective signals oftelephone-lines. Its primary object is to cause the act of makingconnection with the line to automatically determine the excitement ofthe signal to which it is desired to respond. A secondary object is toprovide means for indicating to the operators the identity of thestation signaled. These objects I attain by connecting with theline-circuit equipped with selective-signaling instruments at differentstations a springjack or terminal socket at the central station for eachsubstation, each spring-jack being provided with a device forautomatically causing the operation of a single signaling instrument.The establishment of connection withaparticular spring-jack of theseries thus automatically determines the identity of the selectivesignal which will be operated, while the presence of the connecting-plugin the particular spring-jack indicates the call sent or the stationsignaled.

My invention is of a general nature, but may be illustrated in its usein connection with a particular mode of selective signaling that ofoperating either of two reversely-po- .larized bells bysuitably-directed current in the line, or, in extension of this lattersystem, of operating any of four bells connected in reversely-polarizedpairs with the different line conductors of a complete circuit.

In organizing a" selective-signaling system of this type, it iscustomary to place two bells or other responsive devices in groundbranches from eachside of a metallic line-circuitas, for instance, atelephone-circuit the two sides being normally separated. The two bellsconnected with each side are polarized, adapted to respond to currentsof opposite directions in the circuit. In transmitting signalsselectively by means of such instruments a magneto generator is employedcapable of giving a pulsating current of either direction, preferablyhaving one terminal of its armature grounded and the other adapted forconnection with the sig naling circuit at a moment when itis producingcurrent of the required direction. In applying my invention in such asystem, I provide four spring-jacks or terminal sockets, each having twoinsulated contact members, the like members of the different jacks beingconnected in parallel with each other to the line conductors, and Iarrange in connect-ion with each spring-jack cooperating contactpiecesand circuit connections which shortcircuit or divert the current fromthe generator at the moment when this current is in the wrong directionfor operating the desired signal, and I so arrange the connection of theline conductors with the spring-jacks that when the signaling-current isconnected with any particular springjack only current of suitabledirection for operating the corresponding signal'will be transmittedover the line.

I haveillustrated this form of my invention in the accompanying drawing,and will describe it more specifically with reference to the diagram.

In the drawing, A, B, O, and D designate four substations. The lineconductors 1 and 2 of a metallic telephone-circuit extend to all thesestations and to a central station E, where they terminate inspring-jacks. The signaling and telephonic appliances represented at thesubstations are of well-known type. A receiving-telephone f and a transmitting-telephone g are connected in a bridgeconductor 3 of line-circuit1 2, which is normally interrupted at the switch-contacts of atelephone-switch h. A signal-bell 'L is connected permanently in aground branch 4: from the line-circuit. This bell is a polarized bell ofusual type, but is furnished with a light spring acting upon its pivotedarmature to retain the latter, when the electromagnets are inert, in apredetermined position. The branches 4 at stations A and B are takenfrom line conductor 1; those at stations 0 and D from conductor 2. Thesprings on the armatures of bells i at those stations at which thebranches t are taken from the same line conductor are reverselyarranged. This device permits one hell to be rung by pulsating currentof one polarity or direction over the line conductor and the other bellby oppositely-directed current. The bells branched from the difierentline conductors may of course be operated by closing thesignaling-current to the proper line conductor.

This device is well known in the art and does not require furtherdescription. It may be assumed that a positively-directed current inconductor 1 will actuate the bell at station A, and one of negativepolarity in the same conductor will ring the bell at station B. Likewisea positive current in line 2 will ring bell at station 0 and a negativecurrent that at station D.

At the central station line conductor 1 is connected to earth through animpedancecoil k. Line-wire 2 is led to earth through an annunciator orsignal Z and a battery in.

It will be understood that the bells t at the substations are of suchhigh resistance that the normal constant current from battery m throughline conductor 2 and to earth through them shall be insufficient tooperate the annunciator. hen, however, the telephone is brought into abridge of the circuit 1 2, for use, the current from the battery willfind circuit through the annunciator, over line conductor 2, and throughthe bridge including the telephone at the station, returning by lineconductor 1 and finding circuit through impedance-coil it to earth. Asignal may thus be given to the operator at the cen tral station.

In connection with the line conductors 1 2 are four spring-jacks,(lettered A, B, O, and D, respectively.) Each of these spring-jacks hasa short line-spring n, a long spring n, and a tubular thimble 02 Thesprings 91 of spring-jacks A and D are connected with line conductor 1,the springs n of the same spring-jacks being led to line conductor 2.The springs 11 of spring-jacks B and 0 extend to conductor 2 and springs01 of those jacks to conductor 1. The rings 01* of springjacks A and Care connected with their respective springs 42; the rings of jacks B andD with their springs 71.

The operator at the switchboard E is provided with the usual plugs 0 0,adapted for insertion into the spring-jack, forming the terminal of aplug-circuit 5 6, which includes a calling-key p. This key 1), inaddition to the pair of switch-springs p 132 and their normal andalternate contact-anvils, has a spring 19, which is adapted to registerwith an anvil p when the spring is thrust outward. The spring 133constitutes the terminal of a contact-piece 0 of the calling-plug 0,which is constructed to register with the ring n of a spring-jack intowhich the plug may be inserted. The anvils p 1) of springs 19 and pconstitute the terminals of a generator q of alternating current. Thisgenerator is of peculiar form, although it is well known in the art. Ithas an armature, which may be of the Siemens type, one of whoseterminals is grounded permanently and the other of whose terminals isled to a semicylindrical commutator g, which rotates between twocontact-springs (1 (1 These springs are so placed with relation to thepoint at which the direction of the current in the armature is changedthat spring g receives in each revolution a pulsation ofpositively-directed current, and the spring (1 during the other half ofthe revolution a negatively-directed current.

I do not deem it necessary to trace the operation of signaling from asubstation to the exchange or the process of making connection there.Let it be assumed, for the purpose of illustrating the operation of thisinvention, that the operator wishes to signal to station A. She willinsert plugo into springjack A and operate the key 1). A pulsatorycurrent may now flow from the spring (1 through the contact-points p 29thence through conductor 6 of the plug-circuit to line conductor 1, andthence through branch 4: andbell i at station A to ground. The bell willbe operated by this current. A pulsatory current, whose pulsations occurin the intermissions of current through spring 1 and of oppositedirection, will flow out from spring (1 through conductor 5 oftheplugcircuit to spring it; but from this point a short circuit isprovided through the thimble n to the contact-piece 0 of the plug andthence through the contacts 19 p of the key to earth. Hence nosignaling-current will reach the line conductor 2, and the operation ofthe bell at station D will be prevented.

If the operator were to insert the pluginto spring-jack B, thesignaling-current would flow out from spring g and conductor 5 of theplug-circuit to the spring n of jack B and thence to conductor 1 of theline-circuit, the current from spring (1 of the generator beingshort-circuited at spring at of the springjack and returning to groundthrough the same contact-pieces of the key as before. If the plug wereinserted into spring-jack O, the positively-directed current from springg would reach the line conductor 2 and would operate the bell at station3, the negatively-directed current being short-circnited. Similarlyflheinsertion of the plug into springjack D would cause the operation of thebell at station D. Thus the spring jack into which the plug is inserteddetermines the selective signal connected therewith which shall beoperated, the character of the signal-operating current being modifiedor adapted by the spring-jack and its associated circuit connections forthe actuation of only a particular bell.

When the operator has made a connection with any spring-jack, and hasoperated the signal at the corresponding station, the presence of theplug 0 in that spring-jack indicates to her during the existence of the0011- nection, the station which has been signaled. If it should benecessary to signal the same station again, thismay be done by operatingthe key p; or if it should be necessary to make any charge, as in thecase of a toll connection, the identity of the station signaled isascertained by the presence of the connecting-plug in the correspondingspring-jack.

The broad idea of my invention is subject to more or less extensivemodifications which will occur to those skilled in the art. merousdevices in the form of circuit connections and apparatus may be providedin connection with the spring-jacks A, B, C, and D, to adapt the currentfor the operation of the corresponding signal.

I claim, broadly, as new and desire to secure by Letters Patent 1. Thecombination with a signaling-circuit having several selective signalinginstruments connected with the same conductor thereof, of a separatespring-jack or connection socket for each signaling instrument connectedwith the circuit, a generator of signaling-current and means forapplying it to any spring-jack, and a device in connection with eachspring-jack adapted to determine the operation of the correspondingsignal, as described.

2. The combination with a signaling-circuit, of several responsiveinstruments connected with the same conductor thereof, each adapted tobe actuated by current of a particular character, a spring-jack orconnection-socket connected with the circuit for each responsive device,means for connnecting a source of current with any spring-jack, and adevice in connection with each spring adapted to modify the signalingcurrent, when the source of current is connected with it, to operate thecorresponding responsive device, as described.

3. The combination with a signaling-circuit, of several selectivesignals connected with the same conductor thereof, a springjack for eachsignal also connected with the circuit, a source of current foroperating the signals and means for connecting it with any spring jack,and circuit connections with each springjack for adapting the currentthrough the signaling-circuit to operate the corresponding signal, asdescribed.

4. The combination with a signaling-circuit, of a pair ofoppositely-polarized responsive instruments in the circuit, twospringjacks connected with the circuit, a source of signaling-currentand means for connecting its poles with the similar contact-pieces ofeither spring-jack, the said contact-pieces being reversely connectedwith the circuit, whereby the connection of the source of current witheither spring-jack determines the operation of the correspondingresponsive device.

5. The combination with a metallic signaling-circuit, of a responsivedevice in a ground branch from each limb of the circuit, a springjackfor each instrument connected with the circuit, a source of current anda plug for connecting its poles with similar contactpieces of eitherspring-jack, said source of current being adapted to deliver current toeither line conductor from a ground connection, anauxiliarycontact-piece in each jack, the auxiliary contact-pieces beingconnected with different linecontact-pieces of the two jacks, acontact-piece in the plug registering with the auxiliary contact, andmeans for temporarily grounding the said plug-contact, whereby eitherresponsive device may be operated by inserting the plug into thecorresponding spring-jack.

6. In combination with a metallic-circuit telephone-line, a pair ofoppositely-polarized bells in difierent ground branches from each lineconductor; four spring-jacks, each having two line-contacts connectedwith the line conductors, two diiferent pairs of line-contacts beingconnected with each line conductor, and each having an auxiliarycontactpiece connected with one of its line-contacts, a source ofsignaling-current and a plug for connecting it with any spring-jack; acontact-piece in the plug adapted to register with the auxiliarycontact-piece of a jack into which it may be inserted, andmeans forgrounding the said plug-contact; whereby either of the bells may beoperated by inserting the plug into the corresponding springjack, asdescribed.

In witness whereof I here unto subscribe my name this 16th day of July,A. D. 1895.

FRANK R. MOBERTY. Witnesses:

ELLA EDLER, W. M. CARPENTER.

